diff options
author | Kumar Gala <galak@kernel.crashing.org> | 2007-02-12 23:57:21 -0600 |
---|---|---|
committer | Kumar Gala <galak@kernel.crashing.org> | 2007-02-12 23:57:21 -0600 |
commit | 54c66f6d781e03dc0b23956234963c4911e6d1c0 (patch) | |
tree | 40619a66ae6d8703a57bf681d087ffeabbffd346 /fs/ecryptfs/mmap.c | |
parent | 8ce0a7df6e6117d8814e976d4b7ce6a6b2c9cf93 (diff) | |
parent | 17e0e27020d028a790d97699aff85a43af5be472 (diff) |
Merge branch 'master' into 85xx
Diffstat (limited to 'fs/ecryptfs/mmap.c')
-rw-r--r-- | fs/ecryptfs/mmap.c | 378 |
1 files changed, 199 insertions, 179 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index 06843d24f23..3a6f65c3f14 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -6,7 +6,7 @@ * * Copyright (C) 1997-2003 Erez Zadok * Copyright (C) 2001-2003 Stony Brook University - * Copyright (C) 2004-2006 International Business Machines Corp. + * Copyright (C) 2004-2007 International Business Machines Corp. * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> * * This program is free software; you can redistribute it and/or @@ -234,22 +234,13 @@ int ecryptfs_do_readpage(struct file *file, struct page *page, goto out; } wait_on_page_locked(lower_page); - page_data = (char *)kmap(page); - if (!page_data) { - rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, "Error mapping page\n"); - goto out; - } - lower_page_data = (char *)kmap(lower_page); - if (!lower_page_data) { - rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, "Error mapping page\n"); - kunmap(page); - goto out; - } + page_data = kmap_atomic(page, KM_USER0); + lower_page_data = kmap_atomic(lower_page, KM_USER1); memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE); - kunmap(lower_page); - kunmap(page); + kunmap_atomic(lower_page_data, KM_USER1); + flush_dcache_page(lower_page); + kunmap_atomic(page_data, KM_USER0); + flush_dcache_page(page); rc = 0; out: if (likely(lower_page)) @@ -260,6 +251,33 @@ out: ClearPageUptodate(page); return rc; } +/** + * Header Extent: + * Octets 0-7: Unencrypted file size (big-endian) + * Octets 8-15: eCryptfs special marker + * Octets 16-19: Flags + * Octet 16: File format version number (between 0 and 255) + * Octets 17-18: Reserved + * Octet 19: Bit 1 (lsb): Reserved + * Bit 2: Encrypted? + * Bits 3-8: Reserved + * Octets 20-23: Header extent size (big-endian) + * Octets 24-25: Number of header extents at front of file + * (big-endian) + * Octet 26: Begin RFC 2440 authentication token packet set + */ +static void set_header_info(char *page_virt, + struct ecryptfs_crypt_stat *crypt_stat) +{ + size_t written; + int save_num_header_extents_at_front = + crypt_stat->num_header_extents_at_front; + + crypt_stat->num_header_extents_at_front = 1; + ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written); + crypt_stat->num_header_extents_at_front = + save_num_header_extents_at_front; +} /** * ecryptfs_readpage @@ -279,8 +297,8 @@ static int ecryptfs_readpage(struct file *file, struct page *page) crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode) ->crypt_stat; if (!crypt_stat - || !ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED) - || ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE)) { + || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED) + || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { ecryptfs_printk(KERN_DEBUG, "Passing through unencrypted page\n"); rc = ecryptfs_do_readpage(file, page, page->index); @@ -289,10 +307,51 @@ static int ecryptfs_readpage(struct file *file, struct page *page) "[%d]\n", rc); goto out; } + } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { + if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { + int num_pages_in_header_region = + (crypt_stat->header_extent_size + / PAGE_CACHE_SIZE); + + if (page->index < num_pages_in_header_region) { + char *page_virt; + + page_virt = kmap_atomic(page, KM_USER0); + memset(page_virt, 0, PAGE_CACHE_SIZE); + if (page->index == 0) { + rc = ecryptfs_read_xattr_region( + page_virt, file->f_path.dentry); + set_header_info(page_virt, crypt_stat); + } + kunmap_atomic(page_virt, KM_USER0); + flush_dcache_page(page); + if (rc) { + printk(KERN_ERR "Error reading xattr " + "region\n"); + goto out; + } + } else { + rc = ecryptfs_do_readpage( + file, page, + (page->index + - num_pages_in_header_region)); + if (rc) { + printk(KERN_ERR "Error reading page; " + "rc = [%d]\n", rc); + goto out; + } + } + } else { + rc = ecryptfs_do_readpage(file, page, page->index); + if (rc) { + printk(KERN_ERR "Error reading page; rc = " + "[%d]\n", rc); + goto out; + } + } } else { rc = ecryptfs_decrypt_page(file, page); if (rc) { - ecryptfs_printk(KERN_ERR, "Error decrypting page; " "rc = [%d]\n", rc); goto out; @@ -308,30 +367,27 @@ out: return rc; } +/** + * Called with lower inode mutex held. + */ static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) { struct inode *inode = page->mapping->host; int end_byte_in_page; - int rc = 0; char *page_virt; - if ((i_size_read(inode) / PAGE_CACHE_SIZE) == page->index) { - end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; - if (to > end_byte_in_page) - end_byte_in_page = to; - page_virt = kmap(page); - if (!page_virt) { - rc = -ENOMEM; - ecryptfs_printk(KERN_WARNING, - "Could not map page\n"); - goto out; - } - memset((page_virt + end_byte_in_page), 0, - (PAGE_CACHE_SIZE - end_byte_in_page)); - kunmap(page); - } + if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index) + goto out; + end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; + if (to > end_byte_in_page) + end_byte_in_page = to; + page_virt = kmap_atomic(page, KM_USER0); + memset((page_virt + end_byte_in_page), 0, + (PAGE_CACHE_SIZE - end_byte_in_page)); + kunmap_atomic(page_virt, KM_USER0); + flush_dcache_page(page); out: - return rc; + return 0; } static int ecryptfs_prepare_write(struct file *file, struct page *page, @@ -339,7 +395,6 @@ static int ecryptfs_prepare_write(struct file *file, struct page *page, { int rc = 0; - kmap(page); if (from == 0 && to == PAGE_CACHE_SIZE) goto out; /* If we are writing a full page, it will be up to date. */ @@ -349,30 +404,6 @@ out: return rc; } -int ecryptfs_grab_and_map_lower_page(struct page **lower_page, - char **lower_virt, - struct inode *lower_inode, - unsigned long lower_page_index) -{ - int rc = 0; - - (*lower_page) = grab_cache_page(lower_inode->i_mapping, - lower_page_index); - if (!(*lower_page)) { - ecryptfs_printk(KERN_ERR, "grab_cache_page for " - "lower_page_index = [0x%.16x] failed\n", - lower_page_index); - rc = -EINVAL; - goto out; - } - if (lower_virt) - (*lower_virt) = kmap((*lower_page)); - else - kmap((*lower_page)); -out: - return rc; -} - int ecryptfs_writepage_and_release_lower_page(struct page *lower_page, struct inode *lower_inode, struct writeback_control *wbc) @@ -391,11 +422,8 @@ out: return rc; } -static void ecryptfs_unmap_and_release_lower_page(struct page *lower_page) +static void ecryptfs_release_lower_page(struct page *lower_page) { - kunmap(lower_page); - ecryptfs_printk(KERN_DEBUG, "Unlocking lower page with index = " - "[0x%.16x]\n", lower_page->index); unlock_page(lower_page); page_cache_release(lower_page); } @@ -407,10 +435,9 @@ static void ecryptfs_unmap_and_release_lower_page(struct page *lower_page) * * Returns zero on success; non-zero on error. */ -int -ecryptfs_write_inode_size_to_header(struct file *lower_file, - struct inode *lower_inode, - struct inode *inode) +static int ecryptfs_write_inode_size_to_header(struct file *lower_file, + struct inode *lower_inode, + struct inode *inode) { int rc = 0; struct page *header_page; @@ -418,11 +445,11 @@ ecryptfs_write_inode_size_to_header(struct file *lower_file, const struct address_space_operations *lower_a_ops; u64 file_size; - rc = ecryptfs_grab_and_map_lower_page(&header_page, &header_virt, - lower_inode, 0); - if (rc) { - ecryptfs_printk(KERN_ERR, "grab_cache_page for header page " - "failed\n"); + header_page = grab_cache_page(lower_inode->i_mapping, 0); + if (!header_page) { + ecryptfs_printk(KERN_ERR, "grab_cache_page for " + "lower_page_index 0 failed\n"); + rc = -EINVAL; goto out; } lower_a_ops = lower_inode->i_mapping->a_ops; @@ -430,18 +457,95 @@ ecryptfs_write_inode_size_to_header(struct file *lower_file, file_size = (u64)i_size_read(inode); ecryptfs_printk(KERN_DEBUG, "Writing size: [0x%.16x]\n", file_size); file_size = cpu_to_be64(file_size); + header_virt = kmap_atomic(header_page, KM_USER0); memcpy(header_virt, &file_size, sizeof(u64)); + kunmap_atomic(header_virt, KM_USER0); + flush_dcache_page(header_page); rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8); if (rc < 0) ecryptfs_printk(KERN_ERR, "Error commiting header page " "write\n"); - ecryptfs_unmap_and_release_lower_page(header_page); + ecryptfs_release_lower_page(header_page); lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; mark_inode_dirty_sync(inode); out: return rc; } +static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode, + struct inode *inode, + struct dentry *ecryptfs_dentry, + int lower_i_mutex_held) +{ + ssize_t size; + void *xattr_virt; + struct dentry *lower_dentry; + u64 file_size; + int rc; + + xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); + if (!xattr_virt) { + printk(KERN_ERR "Out of memory whilst attempting to write " + "inode size to xattr\n"); + rc = -ENOMEM; + goto out; + } + lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); + if (!lower_dentry->d_inode->i_op->getxattr) { + printk(KERN_WARNING + "No support for setting xattr in lower filesystem\n"); + rc = -ENOSYS; + kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); + goto out; + } + if (!lower_i_mutex_held) + mutex_lock(&lower_dentry->d_inode->i_mutex); + size = lower_dentry->d_inode->i_op->getxattr(lower_dentry, + ECRYPTFS_XATTR_NAME, + xattr_virt, + PAGE_CACHE_SIZE); + if (!lower_i_mutex_held) + mutex_unlock(&lower_dentry->d_inode->i_mutex); + if (size < 0) + size = 8; + file_size = (u64)i_size_read(inode); + file_size = cpu_to_be64(file_size); + memcpy(xattr_virt, &file_size, sizeof(u64)); + if (!lower_i_mutex_held) + mutex_lock(&lower_dentry->d_inode->i_mutex); + rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, + ECRYPTFS_XATTR_NAME, + xattr_virt, size, 0); + if (!lower_i_mutex_held) + mutex_unlock(&lower_dentry->d_inode->i_mutex); + if (rc) + printk(KERN_ERR "Error whilst attempting to write inode size " + "to lower file xattr; rc = [%d]\n", rc); + kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); +out: + return rc; +} + +int +ecryptfs_write_inode_size_to_metadata(struct file *lower_file, + struct inode *lower_inode, + struct inode *inode, + struct dentry *ecryptfs_dentry, + int lower_i_mutex_held) +{ + struct ecryptfs_crypt_stat *crypt_stat; + + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; + if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) + return ecryptfs_write_inode_size_to_xattr(lower_inode, inode, + ecryptfs_dentry, + lower_i_mutex_held); + else + return ecryptfs_write_inode_size_to_header(lower_file, + lower_inode, + inode); +} + int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode, struct file *lower_file, unsigned long lower_page_index, int byte_offset, @@ -449,10 +553,10 @@ int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode, { int rc = 0; - rc = ecryptfs_grab_and_map_lower_page(lower_page, NULL, lower_inode, - lower_page_index); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error attempting to grab and map " + *lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index); + if (!(*lower_page)) { + rc = -EINVAL; + ecryptfs_printk(KERN_ERR, "Error attempting to grab " "lower page with index [0x%.16x]\n", lower_page_index); goto out; @@ -468,7 +572,7 @@ int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode, } out: if (rc && (*lower_page)) { - ecryptfs_unmap_and_release_lower_page(*lower_page); + ecryptfs_release_lower_page(*lower_page); (*lower_page) = NULL; } return rc; @@ -493,7 +597,7 @@ ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode, "Error committing write; rc = [%d]\n", rc); } else rc = 0; - ecryptfs_unmap_and_release_lower_page(lower_page); + ecryptfs_release_lower_page(lower_page); return rc; } @@ -528,89 +632,7 @@ out: return rc; } -static int -process_new_file(struct ecryptfs_crypt_stat *crypt_stat, - struct file *file, struct inode *inode) -{ - struct page *header_page; - const struct address_space_operations *lower_a_ops; - struct inode *lower_inode; - struct file *lower_file; - char *header_virt; - int rc = 0; - int current_header_page = 0; - int header_pages; - int more_header_data_to_be_written = 1; - - lower_inode = ecryptfs_inode_to_lower(inode); - lower_file = ecryptfs_file_to_lower(file); - lower_a_ops = lower_inode->i_mapping->a_ops; - header_pages = ((crypt_stat->header_extent_size - * crypt_stat->num_header_extents_at_front) - / PAGE_CACHE_SIZE); - BUG_ON(header_pages < 1); - while (current_header_page < header_pages) { - rc = ecryptfs_grab_and_map_lower_page(&header_page, - &header_virt, - lower_inode, - current_header_page); - if (rc) { - ecryptfs_printk(KERN_ERR, "grab_cache_page for " - "header page [%d] failed; rc = [%d]\n", - current_header_page, rc); - goto out; - } - rc = lower_a_ops->prepare_write(lower_file, header_page, 0, - PAGE_CACHE_SIZE); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error preparing to write " - "header page out; rc = [%d]\n", rc); - goto out; - } - memset(header_virt, 0, PAGE_CACHE_SIZE); - if (more_header_data_to_be_written) { - rc = ecryptfs_write_headers_virt(header_virt, - crypt_stat, - file->f_dentry); - if (rc) { - ecryptfs_printk(KERN_WARNING, "Error " - "generating header; rc = " - "[%d]\n", rc); - rc = -EIO; - memset(header_virt, 0, PAGE_CACHE_SIZE); - ecryptfs_unmap_and_release_lower_page( - header_page); - goto out; - } - if (current_header_page == 0) - memset(header_virt, 0, 8); - more_header_data_to_be_written = 0; - } - rc = lower_a_ops->commit_write(lower_file, header_page, 0, - PAGE_CACHE_SIZE); - ecryptfs_unmap_and_release_lower_page(header_page); - if (rc < 0) { - ecryptfs_printk(KERN_ERR, - "Error commiting header page write; " - "rc = [%d]\n", rc); - break; - } - current_header_page++; - } - if (rc >= 0) { - rc = 0; - ecryptfs_printk(KERN_DEBUG, "lower_inode->i_blocks = " - "[0x%.16x]\n", lower_inode->i_blocks); - i_size_write(inode, 0); - lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; - mark_inode_dirty_sync(inode); - } - ecryptfs_printk(KERN_DEBUG, "Clearing ECRYPTFS_NEW_FILE flag in " - "crypt_stat at memory location [%p]\n", crypt_stat); - ECRYPTFS_CLEAR_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE); -out: - return rc; -} +struct kmem_cache *ecryptfs_xattr_cache; /** * ecryptfs_commit_write @@ -640,15 +662,10 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, mutex_lock(&lower_inode->i_mutex); crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode) ->crypt_stat; - if (ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_NEW_FILE)) { + if (crypt_stat->flags & ECRYPTFS_NEW_FILE) { ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " "crypt_stat at memory location [%p]\n", crypt_stat); - rc = process_new_file(crypt_stat, file, inode); - if (rc) { - ecryptfs_printk(KERN_ERR, "Error processing new " - "file; rc = [%d]\n", rc); - goto out; - } + crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE); } else ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" @@ -670,7 +687,6 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, "index [0x%.16x])\n", page->index); goto out; } - rc = 0; inode->i_blocks = lower_inode->i_blocks; pos = (page->index << PAGE_CACHE_SHIFT) + to; if (pos > i_size_read(inode)) { @@ -678,11 +694,15 @@ static int ecryptfs_commit_write(struct file *file, struct page *page, ecryptfs_printk(KERN_DEBUG, "Expanded file size to " "[0x%.16x]\n", i_size_read(inode)); } - ecryptfs_write_inode_size_to_header(lower_file, lower_inode, inode); + rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode, + inode, file->f_dentry, + ECRYPTFS_LOWER_I_MUTEX_HELD); + if (rc) + printk(KERN_ERR "Error writing inode size to metadata; " + "rc = [%d]\n", rc); lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME; mark_inode_dirty_sync(inode); out: - kunmap(page); /* mapped in prior call (prepare_write) */ if (rc < 0) ClearPageUptodate(page); else @@ -707,6 +727,7 @@ int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros) { int rc = 0; struct page *tmp_page; + char *tmp_page_virt; tmp_page = ecryptfs_get1page(file, index); if (IS_ERR(tmp_page)) { @@ -715,28 +736,27 @@ int write_zeros(struct file *file, pgoff_t index, int start, int num_zeros) rc = PTR_ERR(tmp_page); goto out; } - kmap(tmp_page); rc = ecryptfs_prepare_write(file, tmp_page, start, start + num_zeros); if (rc) { ecryptfs_printk(KERN_ERR, "Error preparing to write zero's " "to remainder of page at index [0x%.16x]\n", index); - kunmap(tmp_page); page_cache_release(tmp_page); goto out; } - memset(((char *)page_address(tmp_page) + start), 0, num_zeros); + tmp_page_virt = kmap_atomic(tmp_page, KM_USER0); + memset(((char *)tmp_page_virt + start), 0, num_zeros); + kunmap_atomic(tmp_page_virt, KM_USER0); + flush_dcache_page(tmp_page); rc = ecryptfs_commit_write(file, tmp_page, start, start + num_zeros); if (rc < 0) { ecryptfs_printk(KERN_ERR, "Error attempting to write zero's " "to remainder of page at index [0x%.16x]\n", index); - kunmap(tmp_page); page_cache_release(tmp_page); goto out; } rc = 0; - kunmap(tmp_page); page_cache_release(tmp_page); out: return rc; |